Physicians are notably loath to fully disclose their own errors, but some progress is being made in this area due to institutional policies supporting error disclosure. This article is intended to foster discussion of an especially thorny issue: how clinicians should approach error disclosure when the error was committed by a colleague. As little prior literature exists regarding this dilemma, the authors emphasize a patient-centered approach that begins with a respectful peer-to-peer conversation and does not shirk the need to fully disclose the error. The importance of institutional support, particularly in establishing a just culture that promotes error disclosure, is also emphasized. The article's lead author, Dr. Thomas Gallagher, was interviewed by AHRQ WebM&M in 2009.